Wireless communication protocols such as IEEE 802.11 are designed to support communication between multiple devices operating over the same channel (i.e., a frequency band in a radio-frequency spectrum). In order to transmit data over the channel between two devices when multiple devices are operating the same channel, a channel reservation mechanism is used. One such channel reservation mechanism uses Ready to Send (RTS) and Clear to Send (CTS) control messages to reserve the channel in order to enable the two devices to communicate with minimal or no collisions.
The RTS control message includes, among other information, the following: preambles, frame control information, duration information, the address of the transmitting device, and the address of the receiving device. The CTS control message includes, among other information, the following: preambles, frame control information, duration information, and the address of the receiving device. The devices that receive the RTS control message and/or the CTS control message must receive and subsequently decode the control message where the decoding is performed in a media access control (MAC) layer that is located in a data link layer (DLL) of the devices receiving the message.
The amount of information conveyed in the RTS control message and CTS control message results in a relatively large overhead (both in terms of information transferred, the use of physical layer preambles, and processing time required) and, as a result, degrades performance of the wireless communication between devices over the channel.